Install dmg2img by entering the following commands in the terminal:
sudo apt update sudo apt install dmg2img
Description:
Tool for converting compressed dmg files to hfsplus images
DMG2IMG is a tool which allows converting Apple compressed dmg archives to standard (hfsplus) image disk files. . This tool handles zlib and bzip2 compressed dmg images.
Homepage: http://vu1tur.eu.org/tools/
Version: 1.6.7-1build1
Section: universe/utils